The present invention relates generally to a method and apparatus for providing outside air for combustion in a boiler. More particularly, the present invention relates to a method and apparatus for sealing a boiler""s combustion air intake from inside air and venting combusted air to the outside.
Domestic boilers are used to generate hot water, which may be used to flow through a circuit to provide heating to a facility such as a home or office building. The hot water also may be stored in a hot water tank and used for hot water needs such as running a dishwasher, showers and other domestic hot water uses. Often domestic boilers are located in homes in non-living spaces. For example, they may be located in a utility closet, a basement, a garage, or in other parts of the home that is more associated with storage or utility than with a living space. When boilers are placed in storage or utility areas they are typically mounted on the floor.
Sometimes, for a variety of reasons such as limited storage or utility space, boilers may be located in living spaces within homes or apartments. In order to conserve space, the boiler may be mounted on a wall. There are several desirable features associated with a wall-mounted boiler, such as a small size and/or weight to facilitate the wall mounting. In addition, wall mounted boilers are often located in kitchens or other living spaces, and therefore it is desired that they have an attractive appearance. Most known domestic boilers are configured to be one or the other of a wall mounted boiler, or a floor mounted boiler. This provides a disadvantage in that it is not possible to use a single boiler type for the different applications of wall mounting versus floor mounting. Thus, there is a need for a boiler which is adaptable to a multi-position mounting whether it be wall or floor mounted.
As with any energy-consuming device, increased efficiency is always a goal. Some known boilers have reduced efficiency for a variety of reasons. For example, sometimes room air is used in the combustion chamber and burned and vented to the outside. This results in a loss of efficiency in that the room air which was used for combustion and then vented to the outside may have been first processed by a heating, ventilation, or air conditioning system. A more efficient use of energy would involve the use of bringing in unprocessed outside air for combustion and then venting the combusted outside air back to the outside, thus maintaining room air which has been conditioned within the home. Thus, it is desirable to provide a boiler that burns almost exclusively outside air rather than using room air for combustion.
Another factor which limits known boilers is that many heat exchangers used in boilers are cast iron. Many boilers limit the amount of cooling of the combustion gases because if the combusted gases are cooled too much, the water vapor present in the combustion gases (a byproduct of combustion) will condense and form a condensate which may corrode the cast iron heat exchanger. Thus, using a cast iron heat exchanger limits boiler efficiency because combustion gases must be limited in how much they can be cooled. Limiting the amount of heat harvested from combustion gases limits efficiency because heat is wasted when it is vented out with exhaust gases.
Another limitation of many boilers equipped with cast iron heat exchangers is that some of them use parallel flow configuration. This limitation is related to the restraint of the cooling of the exhaust gases as mentioned above. Parallel flow heat exchangers are a less efficient type of heat exchanger than a counter flow heat exchanger. Counter flow heat exchangers are often not used because they are so efficient that they cool exhaust gases to a temperature that is not acceptable. If counter flow designs are used in cast iron heat exchangers they may need to be controlled in order to maintain the exhaust gases within an exceptable range of temperature to a degree where they may loose efficiency and thus nearly lose the efficiency benefits of being a counter flow heat exchanger. Thus, there is a need for a boiler that is not limited to cooling exhaust gases to a temperature that maintain water vapor in vapor form.
Accordingly, it is desirable to provide a boiler which has an increased efficiency and is not limited to cooling exhaust gases to the temperature ranges that maintain water vapor in vapor form. It is also desirable to provide a boiler that is not limited to the use of parallel flow heat exchangers but can incorporate a counter flow heat exchanging design.
If a boiler is not limited in its cooling of exhaust gases, it will generate condensate as water vapor as the exhaust gases condenses. Accordingly, it is desirable to provide a boiler that can accommodate condensate forming in the boiler and/or can accommodate the corrosive effects of the condensate.
Efficiency may further be increased by pre-heating outside air before combusting it. Accordingly, it may also be desirable to preheat the outside air.
Another way in which efficiency may be lost in boilers is that the controller of the boiler is often in an on/off type control. When additional heating is required, the boiler turns on, when less heating is required the boiler turns off. This type of configuration of on/off control loses efficiency because turning the boiler on may create more heating of hot water than is required. A boiler which may be controlled to increase and decrease output and be turned on and off is a efficient design. In addition, a controller that monitors a variety of boiler conditions can make more accurate control manipulations to the boiler and thus increase its efficiency.
Accordingly, it is desirable to provide a boiler controller that monitors a variety of boiler conditions and controls the boiler to not just a on/off condition but rather on, off, increase or decrease boiler function.
Another desirable feature of nearly all manufactured goods, not just boilers, is to simplify the design. Simplified designs are more cost efficient in production and often require less maintenance than more complex designs. As previously mentioned, many known boilers use cast iron heat exchangers. These cast iron heat exchangers are often cast sections that are sealed and then bolted together. The multiple sections of the heat exchangers and the bolting together create complexity.
Accordingly, it is desirable to provide a heat exchanger without multiple sections, thus simplifying the heat exchanging design.
Simplifying a boiler design to permit more easy installation and maintenance of the boiler as also desirable. For example, location of the electrical connections in multiple places on the boiler complicates installation and maintenance of a boiler because service personnel have to hunt down electrical connections. Providing a boiler with easy connections to ducting and venting will also simplify boiler installation.
Accordingly, a boiler designed to simplify installation and maintenance is desired.
It is therefore a feature and advantage of the present invention to provide a boiler that is configured for installation in multiple positions such as a floor or wall mounting.
It is another feature and advantage of the present invention to provide a heat exchanger that uses primarily outside air for combustion, preheats the outside air, more fully harvests heat from exhaust gases, uses a counter flow heat exchanger and a controller that more accurately and efficiently controls the boiler.
It is another feature and advantage of the present invention to provide a boiler design including a mono block heat exchanger.
It is another feature and advantage of the present invention to provide a boiler that is simple to install and maintain.
The above and other features and advantages are achieved through the use of a novel method and apparatus as herein disclosed. In accordance with one embodiment of the present invention, a boiler is provided. The boiler includes a heat exchanger, a housing defining at least in part a chamber substantially sealed from ambient indoor air in the vicinity of the boiler; an air intake configured to provide air to the chamber for combustion in the heat exchanger; and an exhaust outlet configured to exhaust combustion gases from the heat exchanger to outside the boiler, wherein the heat exchanger is contained in the chamber and the exhaust outlet is at least partially contained in the chamber and the heat exchanger and exhaust outlet are spaced in the chamber to permit air within the chamber to circulate around the heat exchanger and at least part of the exhaust outlet.
In accordance with another embodiment of the present invention, a boiler is provided. The boiler includes means for exchanging heat; means for housing the heat exchanger defining at least in part a chamber substantially sealed from ambient air in the vicinity of the boiler; means for intaking air configured to provide air to the chamber for combustion in the heat exchanging means; and means for exhausting combustion gases from the heat exchanging means to outside the boiler, wherein the heat exchanging means is fully contained in the chamber and the exhausting means is at least partially contained in the chamber and the heat exchanging means and exhausting means are spaced in the chamber to permit air within the chamber to circulate around the heat exchanging means and at least part of the exhausting means outlet.
In accordance with another embodiment of the present invention, a method for increasing the efficiency of a boiler is provided. The method includes: substantially sealing a chamber from ambient indoor air; providing fluid communication between the chamber and outside air; drawing in air from the chamber to a heat exchanger for combustion; and preheating air in the chamber with heat emitted from the heat exchanger.
In accordance with another embodiment of the present invention, at transition piece is provided. The transition piece includes: a tube having a connecting end; a clamp attached to the tube near the connecting end; and a gasket mounted inside the tube near the connecting end, wherein the transition piece is configured to connect to a pipe by fitting the pipe inside the connecting end and engaging the gasket around an outside wall of the pipe in a substantially airtight manner and the clamp is configured to tighten an outside wall of the tube to create a pressfit engagement between the tube and the pipe.
In accordance with another embodiment of the present invention, a transition piece is provided. The transition piece includes: means for directing flow having a connecting end; means for clamping, attached to flow directing means near the connecting end; and means for sealing, mounted inside the flow directing means near the connecting end, wherein the transition piece is configured to connect to a duct by fitting the duct inside the connecting end and engaging the sealing means around an outside wall of the duct in a substantially airtight manner and the clamping means is configured to tighten an outside wall of the flow directing means to create a pressfit engagement between the flow directing means and the duct.
In accordance with another embodiment of the present invention, a method of connecting a transition piece to PVC, ABS or CPVC ductwork is provided. The method includes: inserting a PVC, ABS or CPVC pipe into a connecting end of the transition piece; tightening a clamp provided on the transition piece to create a pressfit engagement between the PVC, ABS or CPVC pipe and the transition piece.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract included below, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.